Pfizer-BioNTech on February 17 announced that the nCoV variant from South Africa could reduce two-thirds of the antibody in its Covid-19 vaccine.
Laboratory studies show that vaccines can still neutralize the virus, but there is no evidence from clinical trials that the new variant reduces the effectiveness of the vaccine. The pharmaceutical company is discussing with officials to invest in upgrading the mRNA vaccine or to release an additional dose of vaccine.
In the study, scientists from Pfizer-BioNTech and the University of Texas Medicine (UTMB) used genetically engineered virus, which had a mutation in the prickly protein similar to the B.1.351 variant found first in South Africa. . Prickly protein is the weapon for viruses to enter human cells and is the main target of many Covid-19 vaccines.
The researchers tested the virus in blood samples of people who had been vaccinated and found that the number of antibodies to neutralize the vaccine was reduced by two-thirds compared to experiments on a common virus in the United States. The new findings are published in the New England Journal of Medicine (NEJM). Since there are no comparable numbers of antibodies needed to fight the virus, it is unclear whether the vaccine is powerless against a variant in South Africa.
However, Pei-Yong Shi, professor from UTMB and co-author of the study, believes the Pfizer vaccine is still resistant to variation. He suggested that the immune response observed in research may still be beyond minimum to protect the body from the virus. The reason is that in previous human trials, the first dose of the Pfizer-BioNTech and Moderna vaccines both showed a lower immune response than in the new study.
Even when the vaccine is ineffective, he said, it still helps people avoid serious illness or death from Covid-19. According to experts, it is the most important thing to keep the health system from being overloaded.
More research is needed on the vaccine’s protection against the B.1.351 variant, including clinical trials and the level of antibodies required to be effective, Shi said. Pfizer-BioNTech said it is doing the same experiment on the vaccine and the variant from Brazil.
Moderna also published on NEJM on Feb. 17, with data showing that antibodies in the vaccine decreased by six times when faced with a variant in South Africa. According to the company, the actual effectiveness of the vaccine against this variant is still unknown.
Mai Dung (Follow Reuters)